There are a great many fields within which it is necessary to verify the identity of a person, in other words to answer the question of whether a certain person is who he claims to be and is thus authorized to use a certain type of equipment. Examples of such equipment are automatic cash dispensers, access systems and various types of electronic equipment, for example mobile telephones and computers.
A conventional manner of carrying out verification is for the user to have a code or a password which he has to input in a verification procedure. If the code is correct, the user is considered to be authorized to use the equipment. However, it can be difficult for a user to remember a large number of different codes and passwords, for which reason alternative ways of verifying the authority and/or identity of a user are necessary. One such alternative method is to have a user register information relating to one or more of his fingerprints in a verification unit, the user then, in a verification procedure, placing the finger or fingers whose print is registered against a surface on the verification unit. The unit analyses whether the fingerprint corresponds to the necessary degree to the fingerprint whose information is stored and, if so, the fingerprint is considered verified, and the user is permitted to use the equipment in question.
Identification by means of fingerprints has traditionally been used mostly within the field of crime prevention, where the question to be answered is not whether a fingerprint corresponds to another to the necessary degree. In that field, an attempt is instead made to establish a match with a specific fingerprint in an extensive register of fingerprints. This type of use of fingerprints does not involve the same great requirement for speed as a verification procedure of the type described above. Speed is also highly desirable in the registering of fingerprint information for use in verification.
Another important parameter, for both registering and verification of fingerprint information, is reliability.